Glass ionomer sealed endodontic post

Abstract

A glass ionomer or resin modified glass ionomer coated blank is combined with glass ionomer or resin modified glass ionomer to create an integral mono-block post. prefabricated glass ionomer or resin modified glass ionomer post (with or without a coated blank) is cemented into the root canal with glass ionomer or resin modified glass ionomer, thereby creating a mono-block post as well as a mono-block core. The glass ionomer or resin modified glass ionomer cement is bonded to the canal wall and also through the bonding of the cement to the post surface of similar material. An alternate methodology involves syringing glass ionomer or resin modified glass ionomer in a malleable, semi-solid state into the post preparation space and a glass ionomer or resin modified glass ionomer coated blank is then inserted into the canal to a distance substantially equal to the depth of the post preparation.

Description

RELATED APPLICATIONS [0001] This application is a continuation-in-part of application Ser. No. 10 / 744,640 dated Dec. 22, 2003 and claims priority under 35 U.S.C. 120 in part therefrom. This application also claims benefit in part under 35 U.S.C. 119(e) from provisional patent application Ser. No. 60 / 436,793, filed Dec. 27, 2002.FIELD OF INVENTION [0002] The present invention relates to Endodontics and, more specifically, the obturation (or the creation of a root canal seal by the use of a sealing material into the tight tapered apical end of a root canal) of the root canal space in a tooth. BACKGROUND [0003] Historically, there have been a number of ways to fill or obturate a root canal space. After a tooth has been thoroughly shaped and debrided of diseased nerve tissue, a filling of the space is required to prevent the ingress of contaminants from both the top section of the root canal (coronal) and the bottom portion (apical). The goal is a hermetic seal of the root canal system....

AI Technical Summary

Benefits of technology

[0019] It is therefore the object of this invention to introduce the concept of synchronicity between the gutta percha core / cone and a machined preparation of a root canal wherein the gutta percha core / cone precisely matches the machined root canal preparation. Consequently, the matching gutta percha core / cone in combination with a next generation glass ionomer cement reduces leakage and achieves a hermetic seal of the root canal. There are properties and designs unique to both the cement and gutta percha that distinguish this technique from any previous methodology. Additionally the gutta percha core / cone is delivered to the tooth (inserted) by use of a “TRANSPORTER”™ delivery vehicle facilitating its use in the endodontic procedure.

[0028] Lastly, the gutta percha has been preferably optionally subject to cryogenic freezing treatment, thereby slightly increasing the surface area of the core / cone and increasing its retention to a glass ionomer cement. The molecular structure of the gutta percha has also been altered by the cryogenic treatment to allow a more intimate contact between the glass ionomer cement and the gutta percha core. The cryogenic treatment additionally adds further rigidity to the gutta percha core / cone making it easier to place in curved canals.

[0031] In summary, the present invention includes an endodontic integral one-piece gutta percha core / cone, which, in combination with an appropriate luting agent properly seals, in a three dimensional manner, a root canal preparation space. Lateral canals can be more effectively filled with sealers that exhibit little or no shrinkage, rather than thermoplastic obturation techniques that produce shrinkage upon cooling. Additionally there are sealers also available in endodontics, such as methylacrylates, that in fact expand slightly rather than shrink, which can fill lateral canals of a root canal more successfully than thermoplastic gutta percha.

Problems solved by technology

The most common cause of failure of root canals is bacterial contamination either through microleakage or contamination during the process.

Initially silver points were used to fill the canal space, but due to leakage problems associated with their shape and the material itself, this technique was abandoned.

However, grasping the obturator manually often obstructs the view of the delivery process of the obturator into the root canal site.

Using a separate tapered carrier core for introducing gutta percha wrapped around it often results in uneven dislodging or stripping of the heated gutta percha from the obturator instrument.

Although popular, this technique was subject to voids as a result of the lateral condensation filling and inaccuracies of adaptation to the root canal wall.

It is very difficult with lateral condensation filling to achieve a three dimensional seal of the root canal system.

Unfortunately, heated gutta percha flows only a few millimeters and shrinks upon cooling, thereby not filling the root canal space it was intended to fill and seal.

While seemingly attractive, heated gutta percha has its limitations.

Shrinkage upon cooling and being technique sensitive are two of the limitations.

The success of this technique had the limitation of being dictated by the success of the preparation.

If the taper of the preparation was not sufficient, the tooth structure could strip (denude) the gutta percha from the carrier, thereby reducing the success of the technique.

A carrier that has a portion stripped of gutta percha increases the risk of bacterial contamination and therefore reduces the prognosis.

Recently, Endodontics has been witness to numerous heated gutta percha techniques that all have the common problem of shrinkage.

Additionally, some of these techniques are technically sensitive making the use of thermoplastic techniques particularly challenging for the general practitioner.

This method had numerous problems such as lack of control of the material, and serious shrinkage that resulted in leakage and bacteria contamination.

Revisement challenges were also a factor if the root canal procedure had to be re-treated.

However, the lack of synchronicity between the root canal preparation and the cone is a problem, as well as the cements, which do not adapt and bond well to the walls of the preparation or to the gutta percha itself.

With the use of the Ultra Dent ENDO-EZE® preparation and the AET™ technique with the ENDO-REZ® resin sealer, there is inconsistency between the root canal preparation and the gutta percha used to fill the root canal space.

Therefore, the lack of a precise match between the preparation and the gutta percha itself results in either excess cement (that will shrink) or the gutta percha cone can hang up in the coronal part of the canal and therefore, not reach the end of the root canal preparation intended to be sealed by the gutta percha.

This can result in leakage and bacterial contamination thereby reducing the prognosis of the case.

This potential problem is the result of a lack of synchronicity between the root canal preparation and the gutta percha cone.

Furthermore, the restoration of endodontically treated teeth has been subject to a lack of synchronicity between the root canal preparation and a prefabricated post.

The consequence of this disparity is less than ideal retention of the post, as well as a weakening of the root when posts of greater dimension, or different shapes, are utilized, thereby compromising the long-term success of the restoration and the tooth.

An additional concern of the restoration of endodontically treated teeth is the lack of a proper coronal seal.

The lack of a three dimensional seal (on top of the gutta percha in the root canal) can result in an ingress of bacterial components.

Bacterial contamination will result in failure of the root canal and remains a serious concern in modern endodontics.

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